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Gregory G Deierlein - One of the best experts on this subject based on the ideXlab platform.
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comparative risk based seismic assessment of 1970s vs modern tall steel moment frames
Journal of Constructional Steel Research, 2019Co-Authors: Carlos Molina Hutt, Tiziana Rossetto, Gregory G DeierleinAbstract:Abstract This study benchmarks the performance of older existing tall steel moment resisting frame Buildings designed following historic Code-prescriptive requirements (1973 Uniform Building Code) against modern design standards (2015 International Building Code). The comparison is based on seismic risk assessments of alternative designs of a 50-story archetype office Building, located at a site in San Francisco, CA. The mean annual frequency collapse risk of the 1973 Building is 28 times greater than the equivalent 2015 Building (28 × 10−4 versus 1 × 10−4), or approximately 13% versus 0.5% probability of collapse in 50 years. The average annual economic loss (based on cost of repair) is 65% higher for the 1973 as compared to the 2015 Building (0.66% versus 0.40% of Building replacement cost). The average annual downtime to re-occupancy for the 1973 Building is 72% longer (8.1 vs 4.7 days) and to functional recovery is about 100% longer (10.4 vs 5.0 days). Building performance evaluations at the design basis earthquake (DBE) and the maximum considered earthquake (MCE) shaking intensities further suggest that 1970s tall steel moment frames have much higher risks of collapse under extreme ground motions and risks of damage and Building closure in moderate earthquakes. Furthermore, while modern Building Code requirements provide acceptable seismic collapse safety, they do not necessarily ensure a level of damage control to assure a swift recovery after a damaging earthquake due to extensive downtime. A set of vulnerability functions are proposed for both archetype Buildings considered in the assessment.
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seismic collapse safety of reinforced concrete Buildings ii comparative assessment of nonductile and ductile moment frames
Journal of Structural Engineering-asce, 2011Co-Authors: Abbie B Liel, Curt B Haselton, Gregory G DeierleinAbstract:This study is the second of two companion papers to examine the seismic collapse safety of reinforced concrete frame Buildings, and examines nonductile moment frames that are representative of those built before the mid-1970s in California. The probabilistic assessment relies on nonlinear dynamic simulation of structural response to calculate the collapse risk, accounting for uncertainties in ground-motion characteristics and structural modeling. The evaluation considers a set of archetypical nonductile RC frame structures of varying height that are designed according to the seismic provisions of the 1967 Uniform Building Code. The results indicate that nonductile RC frame structures have a mean annual frequency of collapse ranging from 5 to 14×10-3 at a typical high-seismic California site, which is approximately 40 times higher than corresponding results for modern Code-conforming special RC moment frames. These metrics demonstrate the effectiveness of ductile detailing and capacity design requirements,...
Fanny Lilian - One of the best experts on this subject based on the ideXlab platform.
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KONTROL KAPASITAS DAYA DUKUNG PONDASI TIANG PANCANG DENGAN METODE FORMULA DINAMIS DAN ANALISIS PACIFIC COAST Uniform Building Code
'Fakultas Teknik Elektronika dan Komputer Universitas Kristen Satya Wacana', 2021Co-Authors: Fanny LilianAbstract:Pondasi merupakan elemen konstruksi yang terletak di bagian terbawah suatu bangunan sipil dan berfungsi untuk meneruskan beban struktur atas (upper structure) ke lapisan tanah dasar (bearing layer) yang ada di bawahnya. Pondasi selain harus mampu menerima beban statis dan dinamis, juga perlu diperhitungkan terhadap sifat tanah ketika menerima efek beban getaran yang menyebabkan tanah mencair (liquefaction) sehingga mengakibatkan daya dukungnya menjadi hilang. Perhitungan kapasitas daya dukung pondasi tiang pancang terhadap kedalaman pemancangan merupakan suatu hal yang perlu diperhatikan dalam suatu perencanaan pondasi. Metode yang digunakan dalam kajian ini disesuaikan dengan kelengkapan data yang diimplementasikan ke dalam rumus-rumus yang digunakan. Tujuan dari penelitian yang dilakukan adalah untuk menganalisa kapasitas daya dukung tiang pancang dengan metode dinamis menggunakan teori yang dipublikasikan oleh Pacific Coast Uniform Building Code (PCUBC). Data yang digunakan untuk menganalisa daya dukung pondasi tiang pancang pada metode formula dinamis ini menggunakan data hasil uji pemancangan (calendering) pada pembangunan Gedung Wisma District Sales Office (DSO) Djarum, Kota Banda Aceh. Hasil yang didapatkan dari penelitian ini berupa nilai daya dukung tiang pancang di lapangan. Daya dukung yang dihasilkan pada penggunaan setiap metode formula dinamis dengan nilai kalandering (final set) 7,0 mm pada PC-237 masing-masing adalah, Danish = 33,695 ton, metode Eytelwein = 23,13 ton, metode CNB = 17,600 ton, metode PCUBC = 14,626 ton, dan metode Hiley = 16,55 ton. Dengan demikian dapat disimpulkan bahwa metode PCUBC merupakan metode yang memiliki nilai daya daya dukung tiang terkecil, sedangkan untuk nilai daya dukung tiang yang terbesar diperoleh dengan menggunakan metode Danish.Kata kunci: Beban struktur atas, kontrol daya dukung, pondasi tiang pancang, formula dinamis, data calendering, Pacific Coast Uniform Building Code (PCUBC)Banda Ace
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KONTROL KAPASITAS DAYA DUKUNG PONDASI TIANG PANCANG DENGAN METODE FORMULA DINAMIS DAN ANALISIS PACIFIC COAST Uniform Building Code
'Fakultas Teknik Elektronika dan Komputer Universitas Kristen Satya Wacana', 2021Co-Authors: Fanny LilianAbstract:Pondasi merupakan elemen konstruksi yang terletak di bagian terbawah suatu bangunan sipil dan berfungsi untuk meneruskan beban struktur atas (upper structure) ke lapisan tanah dasar (bearing layer) yang ada di bawahnya. Pondasi selain harus mampu menerima beban statis dan dinamis, juga perlu diperhitungkan terhadap sifat tanah ketika menerima efek beban getaran yang menyebabkan tanah mencair (liquefaction) sehingga mengakibatkan daya dukungnya menjadi hilang. Perhitungan kapasitas daya dukung pondasi tiang pancang terhadap kedalaman pemancangan merupakan suatu hal yang perlu diperhatikan dalam suatu perencanaan pondasi. Metode yang digunakan dalam kajian ini disesuaikan dengan kelengkapan data yang diimplementasikan ke dalam rumus-rumus yang digunakan. Tujuan dari penelitian yang dilakukan adalah untuk menganalisa kapasitas daya dukung tiang pancang dengan metode dinamis menggunakan teori yang dipublikasikan oleh Pacific Coast Uniform Building Code (PCUBC). Data yang digunakan untuk menganalisa daya dukung pondasi tiang pancang pada metode formula dinamis ini menggunakan data hasil uji pemancangan (calendering) pada pembangunan Gedung Wisma District Sales Office (DSO) Djarum, Kota Banda Aceh. Hasil yang didapatkan dari penelitian ini berupa nilai daya dukung tiang pancang dengan dimensi 25x25 cm dan kedalaman pemancangan 15 meter dari permukaan tanah. Daya dukung yang dihasilkan pada penggunaan setiap metode formula dinamis dengan nilai kalandering (final set) 7,0 mm pada PC-237 masing-masing adalah, Danish = 33,695 ton, metode Eytelwein = 23,13 ton, metode CNB = 17,600 ton, metode PCUBC = 14,626 ton, dan metode Hiley = 16,55 ton. Dengan demikian dapat disimpulkan bahwa metode PCUBC merupakan metode yang memiliki nilai daya daya dukung tiang terkecil, sedangkan untuk nilai daya dukung tiang yang terbesar diperoleh dengan menggunakan metode Danish.Banda Ace
Abbie B Liel - One of the best experts on this subject based on the ideXlab platform.
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seismic collapse safety of reinforced concrete Buildings ii comparative assessment of nonductile and ductile moment frames
Journal of Structural Engineering-asce, 2011Co-Authors: Abbie B Liel, Curt B Haselton, Gregory G DeierleinAbstract:This study is the second of two companion papers to examine the seismic collapse safety of reinforced concrete frame Buildings, and examines nonductile moment frames that are representative of those built before the mid-1970s in California. The probabilistic assessment relies on nonlinear dynamic simulation of structural response to calculate the collapse risk, accounting for uncertainties in ground-motion characteristics and structural modeling. The evaluation considers a set of archetypical nonductile RC frame structures of varying height that are designed according to the seismic provisions of the 1967 Uniform Building Code. The results indicate that nonductile RC frame structures have a mean annual frequency of collapse ranging from 5 to 14×10-3 at a typical high-seismic California site, which is approximately 40 times higher than corresponding results for modern Code-conforming special RC moment frames. These metrics demonstrate the effectiveness of ductile detailing and capacity design requirements,...
Anil K Chopra - One of the best experts on this subject based on the ideXlab platform.
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three dimensional modal pushover analysis of unsymmetric plan Buildings subjected to two components of ground motion
2013Co-Authors: Juan C Reyes, Anil K ChopraAbstract:The original modal pushover analysis (MPA) to estimate seismic demands due to one component of ground motion is extended to consider two horizontal components simultaneously in three-dimensional analysis of Buildings and to estimate internal forces and plastic hinge rotations directly from pushover analyses. Subsequently, the accuracy of the three-dimensional modal pushover analysis (MPA) procedure in estimating engineering demand parameters (EDPs) is evaluated. Eight low- and medium-rise structures were considered. Four intended to represent older Buildings were designed according to the 1985 Uniform Building Code, while four other designs intended to represent newer Buildings were based on the 2006 International Building Code. Median EDP values for these Buildings to 39 two-component ground motions, scaled to two intensity levels, were computed by MPA and nonlinear response history analysis (RHA) and then compared. Even for these ground motions that deform the Buildings significantly into the inelastic range, the MPA offers sufficient degree of accuracy. It is demonstrated that the PMPA, a variant of the MPA procedure, for nonlinear systems is almost as accurate as the well-known standard response spectrum analysis procedure is for linear systems. Thus, for practical applications, the PMPA procedure offers an attractive alternative to nonlinear RHA, whereby seismic demands can be estimated directly from the (elastic) design spectrum. In contrast, the nonlinear static procedure specified in the ASCE/SEI 41-06 standard is demonstrated to grossly underestimate seismic demands for some of the unsymmetric-plan Buildings considered.
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evaluation of three dimensional modal pushover analysis for unsymmetric plan Buildings subjected to two components of ground motion
Earthquake Engineering & Structural Dynamics, 2011Co-Authors: Juan C Reyes, Anil K ChopraAbstract:The accuracy of the three-dimensional modal pushover analysis (MPA) procedure in estimating seismic demands for unsymmetric-plan Buildings due to two horizontal components of ground motion, simultaneously, is evaluated. Eight low-and medium-rise structures were considered. Four intended to represent older Buildings were designed according to the 1985 Uniform Building Code, whereas four other designs intended to represent newer Buildings were based on the 2006 International Building Code. The median seismic demands for these Buildings to 39 two-component ground motions, scaled to two intensity levels, were computed by MPA and nonlinear response history analysis (RHA), and then compared. Even for these ground motions that deform the Buildings significantly into the inelastic range, MPA offers sufficient degree of accuracy. It is demonstrated that PMPA, a variant of the MPA procedure, for nonlinear systems is almost as accurate as the well-known standard response spectrum analysis procedure is for linear systems. Thus, for practical applications, the PMPA procedure offers an attractive alternative to nonlinear RHA, whereby seismic demands can be estimated directly from the (elastic) design spectrum. In contrast, the nonlinear static procedure specified in the ASCE/SEI 41-06 Standard is demonstrated to grossly underestimate seismic demands for some of the unsymmetric-plan Buildings considered. Copyright © 2011 John Wiley & Sons, Ltd.
Curt B Haselton - One of the best experts on this subject based on the ideXlab platform.
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seismic collapse safety of reinforced concrete Buildings ii comparative assessment of nonductile and ductile moment frames
Journal of Structural Engineering-asce, 2011Co-Authors: Abbie B Liel, Curt B Haselton, Gregory G DeierleinAbstract:This study is the second of two companion papers to examine the seismic collapse safety of reinforced concrete frame Buildings, and examines nonductile moment frames that are representative of those built before the mid-1970s in California. The probabilistic assessment relies on nonlinear dynamic simulation of structural response to calculate the collapse risk, accounting for uncertainties in ground-motion characteristics and structural modeling. The evaluation considers a set of archetypical nonductile RC frame structures of varying height that are designed according to the seismic provisions of the 1967 Uniform Building Code. The results indicate that nonductile RC frame structures have a mean annual frequency of collapse ranging from 5 to 14×10-3 at a typical high-seismic California site, which is approximately 40 times higher than corresponding results for modern Code-conforming special RC moment frames. These metrics demonstrate the effectiveness of ductile detailing and capacity design requirements,...
